1. Field of the Invention
The present invention relates to a lens barrel which is driven and controlled when the power of a camera is varied.
2. Description of the Related Art
Conventionally, a lens barrel as disclosed in Jpn. UM Appln. KOKAI Publication No. 1-59210 (hereinafter referred as the conventional lens barrel) is known.
The conventional lens barrel comprises a movable lens frame, an interlock pin provided thereon, and a cam ring having a cam groove with which the interlock pin is engaged. The movable lens frame is movable along the optical axis by moving the interlock pin along the cam groove in accordance with the rotation of the cam ring.
However, in the conventional lens barrel, since the cam groove is formed on the peripheral surface of the cam ring, the length along the optical axis of the cam ring must be as long as the length of a stroke of the movable lens frame along the optical axis plus a. Hence, the size of the camera body in the direction of the optical axis cannot be reduced due to the length of the cam ring.